integration test unable to report using screen

http://logs.openstack.org/60/281560/4/check/gate-bandit-integration-keystone/cd28124/console.html

2016-02-29 21:29:13.113 | bandit runtests: PYTHONHASHSEED='424043074'
2016-02-29 21:29:13.114 | bandit runtests: commands[0] | bandit -r keystone
2016-02-29 21:29:13.491 | [main] INFO running on Python 2.7.6
2016-02-29 21:29:49.680 | 434 [0.. 50.. 100.. 150.. 200.. 250.. 300.. 350.. 400.. ]
2016-02-29 21:29:49.696 | Traceback (most recent call last):
2016-02-29 21:29:49.697 | File ".tox/bandit/bin/bandit", line 10, in <module>
2016-02-29 21:29:49.697 | sys.exit(main())
2016-02-29 21:29:49.698 | File "/home/jenkins/workspace/gate-bandit-integration-keystone/openstack/keystone/.tox/bandit/local/lib/python2.7/site-packages/bandit/cli/main.py", line 342, in main
2016-02-29 21:29:49.698 | args.output_format)
2016-02-29 21:29:49.698 | File "/home/jenkins/workspace/gate-bandit-integration-keystone/openstack/keystone/.tox/bandit/local/lib/python2.7/site-packages/bandit/core/manager.py", line 169, in output_results
2016-02-29 21:29:49.699 | % output_format)
2016-02-29 21:29:49.699 | RuntimeError: Unable to output report using 'screen' formatter.
2016-02-29 21:29:49.995 | ERROR: InvocationError: '/home/jenkins/workspace/gate-bandit-integration-keystone/openstack/keystone/.tox/bandit/bin/bandit -r keystone'
2016-02-29 21:29:49.995 | ___________________________________ summary _______